Category Archives: Research

New critical review of wildland fire impacts on air quality

Dr. Dan Jaffe is the lead author on a critical review that examines the processes that influence wildfires and prescribed fires and their effects on air quality in the U.S. This review, “Wildfire and prescribed burning impacts on air quality in the United States,” is published in the June issue of the Journal of the Air & Waste Management Association. This paper is the result of a collaboration between Dan Jaffe and Susan O’Neill, Narasimhan Larkin, Amara Holder, David Peterson, Jessica Halofsky, and Ana Rappold. These coauthors have brought their range of expertise to the issues related to wildland fires and have examined each of the processes influencing these fires and also the effects of the fires, “including the natural role of wildland fire, forest management, ignitions, emissions, transport, chemistry, and human health impacts.”

Large wildfires in the U.S. are becoming more common, and their emissions of particulate matter (PM) and gaseous compounds negatively impact air quality and human health. The air quality trend in the U.S. has been improving in the last decades. However, seasonal wildfires threaten to undermine this progress in parts of the country. The area burned by wildland fires has grown significantly in the last few decades due to “past forest management practices, climate change, and other human factors.” This has resulted in millions of people experiencing high levels of air pollution. As cities and towns have spread further into wildlands, costs for fire suppression (to protect human developments) and the consequences of fires have increased significantly.

U.S. wildire area burned and federal suppression costs for 1985-2018

Total U.S. wildfire area burned (ha) and federal suppression costs for 1985–2018 scaled to constant (2016) U.S. dollars. Trends for both wildfire area burned and suppression indicate about a four-fold increase over a 30-year period. Data source: National Interagency Fire Center, Fire Information Statistics, accessed December 2, 2019. https://www.nifc.gov/fireInfo/fireInfo_statistics.html.

In this review, Dr. Jaffe and his coauthors describe the current state of the research and identify key data gaps. Their goal is to identify areas that are well understood and areas that need more research. They recommend eight specific areas for future research.

Read the paper here

2 new papers explore methods for measuring biomass burning pollutants

Research by Jaffe Group postdoctoral scholars Dr. James Laing and Dr. Boggarapu Praphulla Chandra has resulted in two new peer-reviewed publications. Both papers examine methods used for measuring air pollutants from wildfires.

The first paper, “Comparison of filter-based absorption measurements of biomass burning aerosol and background aerosol at the Mt. Bachelor Observatory,” was recently published in Aerosol and Air Quality Research. The authors, Dr. James Laing, Dr. Daniel Jaffe, and Dr. Arthur Sedlacek, III, evaluated the upgraded aethalometer (AE33, Magee Scientific) and the new tricolor absorption photometer (TAP, Brechtel) to assess their effectiveness in measuring wildfire aerosol plumes. These instruments measure light-absorbing organic aerosols, which are emitted primarily in biomass burning. Both instruments were deployed at Mt. Bachelor Observatory (MBO) in central Oregon during the summer of 2016. Each instrument uses a similar methodology (“light extinction through an aerosol-laden filter”), but each has a unique set of corrections necessary to address filter-based bias and other issues. The coauthors found that when using the AE33 manufacturer’s recommended settings, correction factors that are larger than the manufacturer’s recommended factor are needed to calculate accurate absorption coefficients and equivalent black carbon.

Read the full paper.

In the second paper, coauthors Dr. Boggarapu Praphulla Chandra, Dr. Crystal McClure, JoAnne Mulligan, and Dr. Daniel Jaffe evaluated the use of dual-bed thermal desorption (TD) tubes with an auto-sampler to sample volatile organic compounds (VOCs). Their paper, “Optimization of a method for the detection of biomass-burning relevant VOCs in urban areas using thermal desorption gas chromatography mass spectrometry,” appeared in the journal Atmosphere in March. For this study, the authors utilized a portable, custom-made “suitcase” sampler, which they deployed in  Boise, ID, during the summer of 2019.

The sampler continuously collected samples of VOCs on the TD tubes for up to six days without the need for continuous on-site monitoring. The tubes were later transferred to the lab for analysis using thermal desorption gas chromatography mass spectrometry (TD-GC-MS) to detect VOCs.

Suitcase thermal desorption VOC auto-sampler 4-2020

(a) Internal view of the volatile organic compound (VOC) suitcase sampler; (b) Flow diagram of the VOC suitcase sampler; (c) Schematic diagram of the dual-bed TD tubes.

They found that “reactive and short-lived VOCs such as acetonitrile (a specific chemical tracer for biomass burning), acetone, n-pentane, isopentane, benzene, toluene, furan, acrolein, 2-butanone, 2,3-butanedione, methacrolein, 2,5- dimethylfuran, and furfural . . . can be quantified reproducibly with a total uncertainty of ≤30% between the collection and analysis, and with storage times of up to 15 days.”

Their research demonstrates the applicability of this flexible method for ambient VOC speciation and determining the influence of forest fire smoke. This sampling method offers a practical alternative for urban air quality monitoring sites because its portability does not require the installation of a complex and expensive instrument and its auto-sampling technique does not require continuous on-site monitoring.

Read the full paper.

New paper explores relationships between PM, ozone, and nitrogen oxides during urban smoke events

Claire Buysse at Mt. Bachelor Observatory, July 29, 2019

Claire Buysse installing equipment at Mt. Bachelor Observatory, July 29, 2019. Photo credit: Mark Stone.

A newly published paper by Claire Buysse and coauthors Aaron Kaulfus, Udaysankar Nair, and Dan Jaffe explores the the impact of wildfire smoke on urban air quality. The paper, published in Environmental Science & Technology, describes the authors’ study of ozone (O3) impacts from smoke on 18 western US cities during July–September 2013–2017. They used monitoring data from ground-based sites and identified smoke using the satellite-based hazard mapping system (HMS) fire and smoke product provided by the National Oceanic and Atmospheric Administration.

Their findings include the following:

  • O3 and particulate matter <2.5 μm in diameter (PM2.5) are elevated at most sites on days influenced by smoke, while nitrogen oxides (NOx) are not consistently elevated at all sites.
  • PM2.5 and O3 exhibit a nonlinear relationship: O3 increases with PM2.5 at low to moderate PM2.5 and then O3 decreases at higher PM2.5.
  • On days influenced by smoke, the rate of increase of morning O3 is higher and the NO/NO2 ratios are lower.
  • The HMS product is useful for identifying smoke. However, because O3 and PM2.5 are elevated on days before and after HMS-identified smoke events, some smoke events are not being detected.

Read the full paper here.

 

Communal support for residents suffering from smoky air

Public officials in several western regions and communities are identifying ways to shield residents from smoke-filled air and to offer communal support when  residents are faced with poor air quality and the impact of climate change. A recent article in the Christian Science Monitor looks at initiatives such as the city of Seattle’s program in which five public buildings were set up as clean-air centers where residents can take shelter if summer wildfire smoke impacts air quality. Dan Jaffe, along with Alex Margarito (UW Bothell graduate) and Rebecca Rickett (UW Bothell student), are working with the city to analyze the effectiveness of these clean-air centers.

In other action, two US senators are introducing “legislation that would provide federal funding to communities to improve ventilation systems in public buildings and set up emergency smoke shelters.” A California state assemblywoman also proposed a state program to improve “ventilation systems in schools, libraries, and community and senior centers” so that residents have a safe haven when air quality is poor.

The particulate matter in smoky air is a health hazard that affects everyone but hits the most vulnerable, including children and the elderly, the hardest. In addition to the physical toll, residents facing wildfire smoke may experience negative mental health effects. Researchers at the University of Montana in Missoula Human Dimensions Lab  found that bringing residents together can help alleviate anxiety. As Libby Metcalf, lab co-director, says, “There’s a need to have a community gathering space to share stories about wildfire…It’s a way for people to feel like they don’t have to face what’s happening on their own.” The American Psychological Association also identifies communal support as an essential remedy to the depression and desolation that people may experience as they cope with the impact of climate change. Officials such as Julia Reed, senior policy adviser to the Seattle mayor, also see the need to bring people together: “All of us see climate change happening right outside our window,” she says. “Coming together is a way to make people feel less helpless.”

Read the full article here.

Wildfire smoke impacts indoor air quality

The last two years in Seattle were the worst on record for wildfire smoke and its impact on air quality. Smoke-filled air contains fine particles of 2.5 microns in diameter or smaller (PM2.5), which pose a significant health risk because they can move deeply into the lungs. When the air quality outside is “unhealthy for all” according to the EPA because the PM2.5 level is above 55 μg/m3, residents are told to remain inside as much as possible. This occurred 2 days in 2017 and 4 days in 2018. The very young, elderly, and sensitive individuals are particularly at risk to air quality with PM2.5 above 35 μg/m3. However, is the air inside that much better? Even with the windows and doors closed, is the air inside at a healthy level during a smoke event?

Worst ever smoke in Seattle on Aug. 21, 2018

Seattle experiences the worst smoke ever (PM2.5 of 110 μg/m3) on August 21, 2018. Photo courtesy of Dan Jaffe.

Last August during a smoke event in the region, Dan Jaffe was curious about the air quality in his office at UW Bothell and elsewhere on campus. He and Alex Margarito, a recent UW Bothell grad who was then a student in Jaffe’s research group, took measurements in Jaffe’s and other offices on campus, in classrooms, and in Jaffe’s Seattle home. They discovered that the inside air was often bad. On August 22, Jaffe measured PM2.5 of 100 μg/m3 inside his office in Discovery Hall at UW Bothell. “You couldn’t tell that it was that bad inside until you actually took the measurements,” Margarito said. “What we found is that the air inside buildings eventually can get near the same levels as what’s outside. So sitting inside is not going to do that well for you.”

This summer Alex Margarito and Rebecca Rickett, a UW Bothell Biochemistry major, are working with Seattle Parks and Recreation to monitor and analyze indoor and outdoor air quality. This project is part of Seattle’s pilot program in which they installed enhanced filtering at five buildings in the city to offer residents an oasis if a smoke event hits the area. The city has also installed several low-cost sensors to measure air quality in several locations around the city.

Joelle Hammerstad, sustainable operations manager at Seattle Parks and Recreation, is excited that the city is partnering with Dan Jaffe and Margarito and Rickett on this project. “Bigger picture, we’re trying to understand the situation at our facilities when we have poor air quality,” Hammerstad said. “Are the measures effective?”

The city is also thinking about climate change. “This is a critical, pivotal moment where we’re refocusing how we’re thinking about climate change. We’re thinking about resilience, adaption,” Hammerstad said. “How do we help front-line communities get through this—communities that don’t have the resources to easily adapt to a changing climate?”

Read more on the UW Bothell website.